781516423 has 4 divisors (see below), whose sum is σ = 798144480. Its totient is φ = 764888368.

The previous prime is 781516409. The next prime is 781516433. The reversal of 781516423 is 324615187.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 781516423 - 2⁵ = 781516391 is a prime.

It is a super-2 number, since 2×781516423² = 1221535838837429858, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (781516433) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8313958 + ... + 8314051.

It is an arithmetic number, because the mean of its divisors is an integer number (199536120).

Almost surely, 2^781516423 is an apocalyptic number.

781516423 is a deficient number, since it is larger than the sum of its proper divisors (16628057).

781516423 is a wasteful number, since it uses less digits than its factorization.

781516423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16628056.

The product of its digits is 40320, while the sum is 37.

The square root of 781516423 is about 27955.6152320066. The cubic root of 781516423 is about 921.1125572386.

It can be divided in two parts, 7815164 and 23, that added together give a palindrome (7815187).

The spelling of 781516423 in words is "seven hundred eighty-one million, five hundred sixteen thousand, four hundred twenty-three".